Effect of Long-Term Cropping of Transgenic Soybean on Soil Microbiome

Transgenic soybean (Glycine max L.) occupies about 80% of the global area planted with this legume, the majority possessing the glyphosate-resistant trait. However, possible impacts of transgenic crops on soil microbial communities are often raised.

Universidade Estadual de Maringá and Embrapa Soja researchers, led by Letícia Carlos Babujia, investigated soil chemical, physical and microbiological properties, and grain yields in long-term field trials involving conventional and nearly isogenic RR transgenic genotypes. The trials were performed at two locations in Brazil with different conditions. Large differences in physical, chemical, and classic microbiological parameters, as well as in grain production were observed between the sites alone.

The metagenomics showed differences in microbial taxonomic and functional abundances. Proteobacteria, Firmicutes and Chlorophyta were higher in the transgenic treatment. The abundance of Proteobacteria contributes to a higher ratio of Proteobacteria:Acidobacteria, which is a bioindicator of superior soil fertility.

Although confirming effects of the transgenic trait on soil microbiome, no differences were recorded in grain yields, probably due to the buffering capacity associated with the high taxonomic and functional microbial diversity observed in all treatments.

For more information, read the full article on Transgenic Research.